How to change tag to minus value in CLX

Hi Guys,

I need to write a routine to calculate direction based on 2 Velocities. I'm trying to implement an ATAN2 VB script i found online into ladder as follows:

If y > 0 Then
If x >= y Then
Atan2 = Atn(y / x)
ElseIf x <= -y Then
Atan2 = Atn(y / x) + Pi
Else
Atan2 = Pi / 2 - Atn(x / y)
End If
Else
If x >= -y Then
Atan2 = Atn(y / x)
ElseIf x <= y Then
Atan2 = Atn(y / x) - Pi
Else
Atan2 = -Atn(x / y) - Pi / 2
End If
End If

The problem i have is here: ElseIf x <= -y Then

I want to use a LEQ instruction but how can I make Y a minus value?

Maybe this cant be done?

-y = y-y-y ?

Perfect. Thank you.

easier yet:

-y = 0 - y

That's too easy! LOL!

-y = y*(-1)

If you are using ladder logic: